fcvt_r - Linux

Overview

fcvt_r is a mathematical library function in Linux that converts a decimal floating-point number to an 80-bit floating-point number. It is typically used for high-precision numerical computations, financial applications, and scientific simulations.

Syntax

double fcvt_r(double value, int ndigits, int *decpt, int *sign)

Parameters

  • value: Decimal floating-point number to be converted.
  • ndigits: Number of significant digits to be converted.
  • decpt: Output parameter that receives the decimal point of the result.
  • sign: Output parameter that receives the sign of the result.

Options/Flags

None.

Examples

Convert the decimal number 123.456 to an 80-bit floating-point number:

#include <math.h>
double value = 123.456;
int ndigits = 6;
int decpt;
int sign;
double result = fcvt_r(value, ndigits, &decpt, &sign);
printf("Result: %.*f\n", decpt, result);

Common Issues

  • Insufficient precision: Ensure that ndigits is sufficient to represent the desired level of precision.
  • Overflow: If the result exceeds the representable range of an 80-bit floating-point number, the function will return HUGE_VAL or -HUGE_VAL.

Integration

fcvt_r can be combined with other mathematical functions, such as sqrt or exp, to perform complex numerical calculations. It is also commonly used in financial applications for accurate currency conversions and scientific simulations for high-fidelity modeling.

Related Commands

  • fcvt: Converts a decimal floating-point number to a fixed-point number.
  • fcvtl: Converts a decimal floating-point number to a long fixed-point number.
  • fcvtns: Converts a decimal floating-point number to a non-standard fixed-point number.